Conventionally, an image forming apparatus forms an image according to an electrographic method. In such an image forming apparatus, foreign materials, such as paper dusts, are attached on a surface of an image bearing member such as photosensitive member. The image forming apparatus is provided with a cleaning device configured to clean the surface of the image bearing member by collecting the foreign materials attached on the surface of the image bearing member. However, there is a possibility that some foreign materials are not collected by the cleaning device and fixed to the surface of the image bearing member. The fixed materials change an electric resistance and an optical transparency of the surface of the image bearing member, thereby causing reduction of image quality.
A known image forming apparatus having a cleaning device supplies tonner on a surface of a photosensitive member and collects foreign materials on the surface of the photosensitive member together with the toner when printing operation is not performed.